How Cosmic Microwave Background Reveals Secrets of the Early Universe!

Transcript

00:00Without this inflation, the universe would have started out too lumpy to ever form such large-scale

00:06structures. But how do scientists know that such a period of inflation took place at all?

00:12One way is by studying fluctuations in the cosmic microwave background, or CMB for short.

00:20The CMB is basically a baby picture of the universe. It is a snapshot of light only 400,000

00:27years after the Big Bang, when the universe was a relatively uniform hot soup of particles.

00:33Since then, the universe has expanded, cooled, and clumped together in ways we recognize today

00:39as galaxies, stars, and planets. But before that, it was smooth and featureless. Researchers studied

00:47the CMB for clues about the early universe because it has the oldest light we can see.

00:52Thanks to NASA's Wilkinson Microwave Anisotropy Probe, also known as WMAP, and later the European

01:01Space Agency's Planck satellite, scientists have mapped the temperature variations in the

01:07CMB to incredible precision. By analyzing these maps, researchers found that the universe was

01:13remarkably uniform in every direction, which supports the idea that the universe inflated

01:19to its present size from an extremely small, hot, dense state. They also confirmed that the

01:25universe is flat on the largest scales, which agrees with the predictions of inflationary models.

01:32This evidence for inflation came from looking at the universe when it was only 400,000 years old.

01:38But scientists have also seen signs of inflation in the universe today. For example, there are some

01:45features on the largest scales that don't appear to match up.

01:48like 10 named

01:49above